Treatment of gasoline



Patented Sept. 14, 1943 TREATMENT OF GASOLINE Joseph A. Chenicek, Chicago, 111., assignor to Universal Oil Products Company, Chicago, 11]., a corporation of Delaware No Drawing. Application January 21, 1941, Serial No. 375,261

12 Claims.

This invention relates to a method for improving the stability of hydrocarbon distillates in so far as color and gum formation are concerned. More particularly the process concerns improved methods of preventing deterioration of cracked gasolines which may be stored over relatively long periods of time in the presence of air.

The use of inhibitors to prevent the depreciation of olefin-containing hydrocarbon distillates such as cracked gasoline has been practiced. Such compounds as alkyl-substituted phenols, aminophenols, fractions of wood tar distillates, etc., have been added to cracked gasoline in relatively minor quantities, of the order of 0.001- 0.10% to inhibit the formation of objectionable oxidation products and prevent loss of color and antiknock properties of said asolines during storage periods. The use of inhibitors has replaced or supplemented such forms of refining as acid-treating, clay-treating and the like. The result has been a material saving in refining costs as well as the conservation of substantial amounts of gasoline which were formerly lost in the refining steps.

The present invention offers a means of improving the inhibiting properties of gasoline gum inhibitors and of effecting material savings in the quantities ,of such materials which may be required adequatel to preserve the valuable properties of gasoline.

In one specific embodiment the present invention comprises a method for treating olefin-containing hydrocarbon distillate such as cracked gasoline to preserve the valuable properties there: of which comprises adding to said distillate a gasoline gum inhibitor together with a relatively minor quantity of an alkylene diamine salt of an organic carboxylic acid.

It has been found that substantial quantities of gasoline gum inhibitor can be replaced with an alkylene diamine salt of a carboxylic acid. The alkylene diamines have the general structural formula:

wherein R, R and R" may be hydrogen atoms, aryl groups, or alkyl groups, R. may be a hydroxy group, and. wherein R and B" may be amino-alkyl or hydroxy-alkyl groups. The groups substituted in these positions may or may not be the same in any given instance. a: may be zero or an integer, and x is an integer. Such compounds ma include ethylene dlamine, dl-

ethylene triamine, triethylene tetramine, 1,3-dlamino propane, 1,2-diamino propane, 1,3-di- I amino propanol, hydroxy ethyl-ethylene diamine, di-o-tolyl ethylene diamine, diphenyl ethylene diamine etc. Compounds of this nature are caused to react with organic substances having an acidic reaction, such a carboxylic acids of which acetic acid, ethylhexoic acid, butyric acid, stearic acid, palimitic acid, oleic acid and the like are representative.

It should be understood that the various compounds of the present invention are not equivalent in their action and that equal quantities of one cannot necessarily be substituted for another. The effectiveness of the compounds depends upon the compounds themselves and their solubility in gasoline, the quantity used as well as upon theis to be inhibited by the present method.

The quantity of the compounds of this invention used in the gasoline is of the order of 0.0001-0.0l%. The exact quantity required is a function of theinhibitor and of the gasoline as well as the desired stability of the gasoline treated. The compounds of this invention are not of themselves gum inhibitors and the effect observed is not, therefore, such as might be expected by the mixing of two gasoline gum inhibitors. When added alone to cracked gasoline in amounts up to approximately 0.1%, little or no increase in the oxygen bomb induction period is to be observed and storage test indicate that no protection is obtained for the gasoline under storage conditions. However, when an inhibitor.

A Pennsylvania. cracked gasoline was treated with a gum inhibitor comprising N-butyl aminophenol in concentrations of 0.01%. To this gasoline was added equivalent quantities of various compounds of the present invention. The gasoline was then subjected to the oxygen bomb induction test with and without the added gum inhibitor and the added compounds of the invention. The results of the test are shown in the following table.

Ind. period, min.

Blank gasoline 150 +0.01% commercial inhibitor 450 +0.01% commercial inhibitor+0.0024% diethylene triamine monoethylhexoate +0.01% commercial inhibitor+0.0038% diethylene triamine diethylhexoate +0.01% commercial inhibitor+0.0038% diethylene triamine monostearate- +0.01% commercial inhibitor+0.0065% diethylene triamine distearate 630 +0.01% commercial inhibitor +0.0034% ethylene diamine monoethylhexoate +0.01% commercial inhibitor+0.0058% ethylene diamine diethylhexoate +0.01% commercial inhibitor+0.0057% ethylene diamine monostearate commercial inhibitor+0.010%

ethylene diamine distearatecommercial inhibitor+0.00l% diethylene triamine commercial inhibitor+0.001%

ethylene diamine 610 It will be noted that a material increase in induction period occurs when the inhibitor is used, together with the various compounds shown. Supplementary tests wherein the alkylene polyamine salts of the various acids were tested in the abs'enceof the inhibitor show that the compounds had no appreciable inhibiting effect up to concentrations of approximately 0.05%. The data also show that the compounds of this invention are somewhat more efiective than the corresponding alkylene diamine when used in ratios of their molecular weights.

I claim as my invention:

1. A method for improving the stability of a hydrocarbon distillate with respect to gum formation which comprises adding thereto a gum coo inhibitor together with an alkylene polyamine salt of an organic acid, said salt containing at least three amino radicals.

2. In a process for stabilizing olefins containing gasoline against depreciation in storage by adding thereto a gasoline gum inhibitor, the improvement which comprises adding to such inhibited gasoline a relatively minor quantity.

of an alkylene polyamine salt of an organicacid said salt containing at least three amino radicals.

3. A process for preventing gum formation in cracked gasoline which comprises adding thereto a gasoline gum inhibitor and an alkylene polyamine salt of an organic acid, said salt containing at least three amino radicals.

4. A process for preventing gum formation in cracked gasoline whichcomprises adding thereto a gasoline gum inhibitor comprising an alkylsubstituted amiriophenol and an alkylene polyamine salt of an organic acid, said salt containing at least three amino radicals.

5. A process for preventing gum formation in cracked gasoline which comprises adding thereto a salt of an organic acid and an alkylene polyamine, said salt containing at least three amino radicals.

6. A process for preventing gum formation in cracked gasoline which comprises adding to said gasoline an inhibitor comprising a hardwood tar distillate boiling in the range of approximately 240-280" C. and an organic salt of an alkylene polyamine, said salt containing at least three amino radicals.

7. A process for preventing gum formation in cracked gasoline which comprises addingthereto a gasoline gum inhibitor and diethylene triamine distearate.

8. A method for preventing gum formation in cracked gasoline which comprises adding thereto a gasoline gum inhibitor and diethylene triamine monostearate.

9. A method for preventing gum formation in cracked gasoline which comprises adding thereto a gasoline gum inhibitor and an ethylene triamine stearate.

10. Motor fuel comprising olefinic gasoline containing a gum inhibitor and an alkylene polyamine salt of an organic carboxylic acid, said salt containing at least three amino radicals.

11. Motor fuel comprising olefinic gasoline containing a gum inhibitor and an alkylene triamine salt of an organic carboxylic acid.

12. A method for increasing the stability of olefinic distillates which comprises adding to the distillate a gum inhibitor and an alkylene triamine salt of an organic carboxylic acid.

' JOSEPH A. CHENICEK. 

